Insulating means for an electromagnetic relay

ABSTRACT

Insulating device for the coil of a relay and particularly a miniaturized relay, in the form of an insulating receptacle for the relay coil. The receptacle receives the coil and extends about the coil on three sides. The insulating receptacle may be molded or drawn from a plastic insulating material and besides insulating the coil from the contact springs of the relay, serves to insulate the coil and contacts from the legs of the yoke, which may be parallel to the coil.

United States Patent 1 Kobler et al.

INSULATING MEANS FOR AN ELECTROMAGNETIC RELAY Inventors: Ulrich Kobler;Harry Schroder,

both of Munich, Germany Assignee: Siemens Aktiengesellschaft, Berlin &

Munich, Germany Filed: Nov. 7, 1973 Appl. No.: 413,649

Foreign Application Priority Data Nov. 29, 1972 Germany 2258479 US. Cl335/278, 336/198 Int. Cl. H01f 7/00 Field of Search 335/278, 279, 282;

References Cited UNITED STATES PATENTS 12/1966 Brown 335/278 X Oct. 1,1974 3,701,066 10/1972 Bosch et al. 335/279 X 3,750,073 7/1973 Okano336/208 X 3,775,718 ll/1973 Kanawa.....

3,778,719 l2/1973 Kanawa 335/278 Primary Examiner-G. Harris Attorney,Agent, or Firm-Hill, Gross, Simpson, Van Santen, Steadman, Chiara &Simpson [5 7 ABSTRACT Insulating device for the coil of a relay andparticularly a miniaturized relay, in the form of an insulatingreceptacle for the relay coil. The receptacle receives the coil andextends about the coil on three sides. The insulating receptacle may bemolded or drawn from a plastic insulating material and besidesinsulating the coil from the contactsprings of the relay, serves toinsulate the coil and contacts from the legs of the yoke, which may beparallel to the coil.

10 Claims, 8 Drawing Figures PATENIEUBBH 1514 I SHEET 1 [If 3 PATENIEunH m4 sum 20; 3

PATENIEDUETI m4 3.839.690 SHEET 3m a" INSULATING MEANS FOR ANELECTROMAGNETIC RELAY FIELD OF THE INVENTION Insulating device for thecoils of miniaturized relays.

BACKGROUND, SUMMARY AND ADVANTAGES OF INVENTION An important problem inrelay design and particularly miniaturized flat relays, is to provideadequate insulation for all of the conductive parts of the relay, whichmay have different potentials, and including the coil winding, thecontacts of the relay and the yoke, which in most cases, is grounded.

This problem is especially present in miniaturized flat relays where thecontact springs are arranged close to the coil winding and where, inaddition, one of several yoke legs of the yoke may run parallel to thecoil. Where such a relay is used for the switching of heavier currentsthan normal, special insulating measures are necessary in order toguarantee a perfect and safe functioning of the relay.

A known relay of this type is shown and described in the SiemensMagazine of 1968, on pages 259-261. In such relays, it has been commonpractice to wind an insulation band around the coil winding and, inaddition, to provide an insulating plate between the coil and the springcontact set. Further, the coil connections and the yoke have requiredinsulation which was attained by the insertion of individual insulatingparts. With such relays, the wrapping of the coil with insulation had tobe carried out by hand with great care in order to assure adequiteinsulation of the parts of the relay and a clean contact at the coilflanges. This was a timeconsuming operation, greatly increasing the costthe the relay and many times resulted in an improperly functioningrelay.

The advantages of the present invention, among others, are that itcreates an insulating arrangement of the relay providing adequateinsulation for the parts of the relay, and easily assembled andproduced.

This is attained by the provision of an insulating receptacle receivinga coil and insulating the coil from the contact-making parts andsurrounding the coil, except for the top thereof.

In accordance with the principles of the present invention, theinsulating receptacle replaces the former wound insulation and variousadditional insulating parts which cannot be produced by automatedequipment, and requires a minimum of assembly line work and furthermakes it possible for the assembly of the relay to be mechanized.

This further avoids winding of the coil with insulating material byproviding an insulating receptacle in its final form prior to assembly.

In a preferred embodiment of the invention illustrated, the insulatingreceptacle is particularly adapted to a flat relay having an E-shapedcore yoke. The high side walls of the insulating receptacle are locatedbetween the coil winding and the outer legs of the core yoke and thereceptacle partially extends about the coil flanges to increase thecreep distances to the longest amount possible.

A further advantage of the insulating receptacle is that the receptaclemay be provided with end walls grooved to receive the coil flanges.

A further advantageous development of the invention is that theinsulating receptacle may be provided with prolongations forming endpockets protecting the coil connections.

Where the insulating receptacle is used with a relay having an E-shapedmagnetic system, the receptacle covers the yoke and the resting of thefoil on the yoke can be prevented by insulating projections at one endof the receptacle to prevent the flow of creep current between the coilconnections and the yoke and to provide an air distance around thereceptacle wall providing efficient insulating conditions.

Other objects, features and advantages of the invention will be readilyapparent from the following description of preferred embodimentsthereof, taken in conjunction with the accompanying drawings, althoughvariations and modifications may be effected without departing from thespirit and scope of the novel concepts of the disclosure.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a forming ofinsulating receptacle constructed in accordance with the principles ofthe present invention.

FIG. 2 illustrates a partial fragmentary longitudinal sectional viewtaken through a relay utilizing the insulating receptacle of theinvention showing the relay coil and insulating receptacle inlongitudinal section, with parts removed.

FIG. 3 is a partial fragmentary top plan view illustrating theinsulating receptacle and relay coil as viewed from the top thereof.

FIG. 4 is a perspective view showing a modified form of insulatingreceptacle which may be used to carry out the principles of the presentinvention.

FIG. 5 is a perspective view of a miniaturized electromagnetic relayshowing the coil insulated by the insulating receptacle of FIG. 4.

FIG. 6 is a view in side elevation of the miniaturized relay shown inFIG. 5 with certain parts broken away and certain other parts shown insection.

FIG. 7 is a partial fragmentary perspective view illustrating theassembly of an E-shaped yoke to the insulating receptacle of FIG. 4; and

FIG. 8 is a perspective view further illustrating the assembly of theyoke to the receptacle and armature of the relay.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION In the embodimentof the invention illustrated in FIGS. 1, 2 and 3, we have shown in FIG.1 an insulating receptacle 1 constructed in accordance with theprinciples of the present invention having parallel side walls 1a and lbprojecting upwardly from opposite sides of a base 1e of the receptacle.The side walls 1a and lb are of greater height than the coil winding andare connected together by end walls having similar openings therein toform ribs 10 and 1d extending upwardly of the base 1e and inwardly ofsaid side walls. As shown in FIGS. 2 and 3, a relay coil 2 including awinding 3 wound in a recessed portion 2e of a body 2d for the relay isshown as mounted in the receptacle 1. The body 2d is formed from asuitable plastic insulating material and has outwardly opening recesses2c and 2f opening to the bottom and sides thereof accommodating the bodyand winding 3 to be received in the receptacle l with the end ribs 1 cand 1d extending in said recesses 20 and 2f to provide insulation forthe coil and create a good insulation density. The body 2d is also shownas having a central passageway 4 extending along the axis of the coilwithin which may be mounted an iron core (not shown). The body 2d isprovided with an armature stop 2a extending from one end thereof and anextension 2b supporting a yoke (not shown).

A base 5 for the relay has a pair of contact springs 6 and 6a havingcontacts 6c and 6d engageable with each other and insulated from thecoil winding by the insulating receptacle 1. The contact springs 6 and6a are shown as being leaf springs secured to the base 5 and their endsopposite the contacts 6c and 6d.

The coil 2 and body 2d, as shown in FIGS. 2 and 3, are thus recessed inthe ribs 1c and 1d of the receptacle 1 extending within the grooves and2f of the body 2d, which extend along the bottom and sides of the coilat least to the top surface thereof. The side walls are thus relativelyhigh and project upwardly from the base 12 a distance greater than thediameter of the wound coil to adequately insulate the coil and providesufficient creep distance for the coil winding 3.

In FIGS. 4 through 8, we have shown a more sophisticated development ofthe insulating receptacle from that shown in FIGS. 1, 2 and 3. Thesefigures show an insulating receptacle l1 constructed on principlessimilar to the insulating receptacle 1, in which the side walls of thereceptacle extend upwardly from the bottom of the receptacle a greaterdistance than the diameter of the coil.

The receptacle has opposite end walls 13 and 16 cut away to receive thebody 15 of the relay and wound coil 12 and provide sufficient creep andair distance between the yoke 17 of the relay and the potentialconducting contact spring (not shown).

The armature and yoke are made from metal, such as iron. The armaturecompletes the flux path of the yoke. The yoke 17 is of a conventionalE-shaped form including a transverse bar 22, parallel legs 17a and acenter leg 27 extending from the transverse bar 22 through the centralpassageway (not shown) of the coil 12 and forming a core for the coil.The yoke or core passageway is formed in the coil body 15 about whichthe coil 12 is wound between flanges 12a in a manner similar to thatshown in FIG. 2. The leaf spring 38 are secured to the legs 170 at oneof their ends on studs 29 and extend along said legs and are clamped tothe legs of the armature 34 by claw-like ends 35 of said springs. Thesprings 38 may be attached to the studs 29, to extend along the legs 17aof the yoke by riveting or any other suitable manner, after the yoke hasbeen assembled to the receptacle 11.

The ends of the body 15 are in contact with soldering lugs 18 conductingcurrent to the coil. The lugs 18 are protected by pockets 19 formed bywidened extensions of the side walls of the receptacle and extending tothe height of the side walls of the receptacle 11. The pockets 19 have abottom wall 1% extending across the opening 16 and protect the solderinglugs 18 from the yoke 17 and surround the soldering lugs 18 along thebottom ends and sides thereof and extend above said lugs.

The outer ends of the vertical walls of the pockets l9 terminate intothickened tapering inwardly extending end portions 20 extending towardeach other along the bottom wall 19a at the outer end thereof, tocompletely protect the soldering lugs 18 and provide the required airdistance between the soldering points of the soldering lugs 18 and anyexposed yoke part.

Moreover, in order to prevent contacting of the receptacle with the yoke17 in the area of a cross-bar 22 of the yoke 17, the receptacle isprovided with one or more projections 21 depending from the bottom all19a and engaging the end of the yoke to avoid unfavorable short creepdistances between the soldering lugs and the cross-bar 22 of the yoke.

The cross-bar 22 of the yoke is further insulated from coil energizingplugs 23 by an insulating extension of the bottom wall 19a in the formof a foil 24, formed as a part of the bottom wall to normally dependfrom said bottom wall, but to hinge upwardly to accommodate insertion ofthe yoke along the receptacle. This further protects the connectingplugs 23 from the yoke 17, particularly along the transverse bar 22thereof. The foil 24 extends entirely across the receptacle to assureadequate protection of the cross-bar 22 of the yoke 17. v

The insulating receptacles 1 and 11 may be made from a suitable plasticinsulating material, deep-drawn to the final shape, with the necessaryindentations, bulges, projections and rib produced by corresponding formshaping. One form of material is a polycarbonate known to the tradeunder the German Trademark of the firm Bayer Leverkusen as Makrofol."Other forms of plastic insulating materials may also be used.

- In order to produce the recesses 25 and 26 in the end walls 13 and 16of the receptacle, after deep-drawing of the receptacle, the oppositewalls 13 and 16 are shown-in FIG. 6 as extending generally parallel, butslightly inclined relative to the vertical at an angle of from 1 to 10,shown in FIG. 6 as being an angle a and substantially 10. This anglecorresponds to the inclination of the drawing form and is to provide theproper draft. A cutting tool (not shown) may then operate perpendicularto this angle to cut out the opening 26 and at the same time take outthe vertical piece from the wall 13 and cut the opening 25.

Prior to the assembly of the yoke 17 to be finished insulatingreceptacle 11, the coil 12 is wound about the body 15 between endflanges 12a and 12b of the body as shown in FIG. 5. The coil and bodyare then positioned in the correct position relative to the receptacle11. The E-shaped yoke may then be inserted with the core 27 of the yokeextending through the central passageway extending along the body 15along the axis of the coil in the direction of the arrow 28 (FIG. 7). Inorder to do this, the foil or extension 24 may be hinged upwardly asindicated by dashed lines in FIG. 6. The extension 24 bulges upwardly inthe regions of the lugs 29, as indicated by reference numeral 30. Tofacilitate insertion of the yoke, the extension 24 has a leading edge 31which may be turned outwardly at its free end about a radius 32 toprevent the catching of the edge 33 of the cross-bar 22 with saidextension. After the insertion of the yoke with the legs 17a extendingalong opposite sides of the insulating receptacle, the extension 24 maybe hinged downwardly to cover the crossbar 22 of the yoke and insulatethe front side of said cross-bar from the electrical parts of the relay.

In FIG. 8 the coil 12 and yoke 17 are shown as completely assembled tothe receptacle 11 with the armature 34 resiliently attached thereto bythe leaf spring 38 free from the side walls of the receptacle, giving itcomplete freedom to properly perform its function and insulating thearmature and yoke with respect to the coil and its energizingconnections, to assure safe functioning of the relay.

It may be seen from the foregoing that the insulating receptacle of thepresent invention, as shown in all of the figures of the drawings,provides an integral preformed insulating device assuring safe andadequate insulation for the coil and simplifying the insulation of thecoil and assembly of the relay, making it possible to assemble the relaywithout first winding the coil with an insulating covering.

It should further be understood that while the receptacle in FIGS. 4through 8 is more sophisticated than that shown in FIGS. 1 through 3,the insulating principles of both receptacles are the same and thereceptacles of both figures serve as a pre-formed effective insulatingmeans for the coil of a miniaturized relay and substantially simplifythe assembly thereof, and thus reduce the-cost of the relay.

We claim as our invention:

1. In a pre-formed insulating means for the coil of an electromagneticrelay including the coil,

an iron yoke forming a core for the coil,

contact-making parts arranged in proximity to the coil,

and a body forming a mounting for the coil, the improvement comprisingan insulating receptacle receiving the coil and its body and having abase and parallel side walls extending along the bottom and each side ofthe coil and end walls having aligned openings therein and recessedwithin the coil body.

2. The insulating means of claim 1,

wherein the yoke is an iron E-shaped yoke having a transverse bar, acenter leg forming the core for the coil and parallel legs extendingfrom said transverse bar along opposite sides of the coil, and

wherein the receptacle extends between the coil and outer parallel legsof the yoke and insulates said legs from the coil.

3. The insulating means of claim 1,

wherein the coil is wound about an insulating body including parallelflanges, between which the coil is wound,

and

wherein the body forms a stop for the yoke and further insulates theyoke from the coil.

4. The insulating means of claim 3, wherein the receptacle has pocketsat one end thereof extending laterally of opposite side walls of thereceptacle, and forming insulating pockets for the energizingconnections to the coil.

5. The insulating means of claim 4, wherein the pockets have a bottomwall extending across the receptacle and over the transverse bar of theyoke to form an insulating means therefor.

6. The insulating means of claim 5,

wherein the bottom for the pocket has an insulating extension extendingoutwardly of the bottom, hinged downwardly upon assembly of the yoke andcore to the coil, and

wherein the side walls of the receptacle extend between the coil andouter legs of the yoke and the hinged extension hinges upwardly toaccommodate insertion of the yoke to the receptacle and downwardly uponinsertion of the yoke to insulate the cross-bar of the yoke from thecoil and electrical energizing connections for the coil.

7. The insulating means of claim 5, wherein the bottom wall connectingthe pockets together has a lug depending therefrom for engaging thecross-bar upon insertion of the yoke, to space said bottom wall abovethe cross-bar as the yoke is inserted in position.

8. The insulating means of claim 6, wherein the hinged extension has anarcuate outer edge forming an entering edge for the cross-bar and yokeand preventing interference between said hinged extension and yoke asthe yoke is inserted along the sides and center of the coil.

9. The insulating means of claim 6, wherein the outer legs of the yokeeach have a stud projecting upwardly therefrom forming a connectingmeans for the armature of the relay and the hinged extension hasoutwardly extending roof-shaped bulges in alignment with the lugs on theyoke legs, to prevent interference between the hinged extension andstuds on the yoke legs upon assembly of the yoke to the coil andinsulating receptacle.

10. The insulating receptacle of claim 8, wherein the insulatingreceptacle is a deep-drawn plastic part made from a plastic insulatingmaterial and opposite end walls of the receptacle extend parallel toeach other and are inclined relative to the vertical at an angle a.

1. In a pre-formed insulating means for the coil of an electromagneticrelay including the coil, an iron yoke forming a core for the coil,contact-making parts arranged in proximity to the coil, and a bodyforming a mounting for the coil, the improvemEnt comprising aninsulating receptacle receiving the coil and its body and having a baseand parallel side walls extending along the bottom and each side of thecoil and end walls having aligned openings therein and recessed withinthe coil body.
 2. The insulating means of claim 1, wherein the yoke isan iron E-shaped yoke having a transverse bar, a center leg forming thecore for the coil and parallel legs extending from said transverse baralong opposite sides of the coil, and wherein the receptacle extendsbetween the coil and outer parallel legs of the yoke and insulates saidlegs from the coil.
 3. The insulating means of claim 1, wherein the coilis wound about an insulating body including parallel flanges, betweenwhich the coil is wound, and wherein the body forms a stop for the yokeand further insulates the yoke from the coil.
 4. The insulating means ofclaim 3, wherein the receptacle has pockets at one end thereof extendinglaterally of opposite side walls of the receptacle, and forminginsulating pockets for the energizing connections to the coil.
 5. Theinsulating means of claim 4, wherein the pockets have a bottom wallextending across the receptacle and over the transverse bar of the yoketo form an insulating means therefor.
 6. The insulating means of claim5, wherein the bottom for the pocket has an insulating extensionextending outwardly of the bottom, hinged downwardly upon assembly ofthe yoke and core to the coil, and wherein the side walls of thereceptacle extend between the coil and outer legs of the yoke and thehinged extension hinges upwardly to accommodate insertion of the yoke tothe receptacle and downwardly upon insertion of the yoke to insulate thecross-bar of the yoke from the coil and electrical energizingconnections for the coil.
 7. The insulating means of claim 5, whereinthe bottom wall connecting the pockets together has a lug dependingtherefrom for engaging the cross-bar upon insertion of the yoke, tospace said bottom wall above the cross-bar as the yoke is inserted inposition.
 8. The insulating means of claim 6, wherein the hingedextension has an arcuate outer edge forming an entering edge for thecross-bar and yoke and preventing interference between said hingedextension and yoke as the yoke is inserted along the sides and center ofthe coil.
 9. The insulating means of claim 6, wherein the outer legs ofthe yoke each have a stud projecting upwardly therefrom forming aconnecting means for the armature of the relay and the hinged extensionhas outwardly extending roof-shaped bulges in alignment with the lugs onthe yoke legs, to prevent interference between the hinged extension andstuds on the yoke legs upon assembly of the yoke to the coil andinsulating receptacle.
 10. The insulating receptacle of claim 8, whereinthe insulating receptacle is a deep-drawn plastic part made from aplastic insulating material and opposite end walls of the receptacleextend parallel to each other and are inclined relative to the verticalat an angle a.